This long-term research program seeks elucidation of genetic-biochemical parameters controlling differentiation and developmental processes in mammalian cells. A series of cell mutants, and hybrids is being prepared involving the standard Chinese hamster ovary culture; and cells from human and animal tissues taken at different stages of development and from various developmental disease situations. Studies will be conducted on the growth, morphological, and biochemical effects produced by cyclic AMP derivatives and selected hormones. The methodologies include somatic cell genetic analysis; study of biochemical pathways; immunogenetics; electron-spin resonance and other membrane studies; and scanning and transmission electron microscopy.